This study seeks to contribute to improved life prediction analysis of high temperature structures. When failure occurs under high temperature cyclic loading, material damaged by cavity growth and crack begins to propagate along grain boundary with higher growth rate than room temperature. To consider this cavity damaging effect, creep damage model developed by Lee \& Miller was introduced and new creep-fatigue-interaction damage model was developed. Using this model, computer simulation of life prediction has been performed for 304 SS under various loading shapes. To develop the simulation, stress analysis program which developed at Stanford Univ. was combined with the creep-fatigue interaction model.
